What is a coronary calcium score?

A coronary calcium score, or CAC score, shows how much calcified plaque has built up in the arteries that supply your heart. You get it from a quick, low-dose CT scan, with no contrast agent. Calcium in these arteries is a sign of atherosclerosis, plaque build-up in the artery walls that can lead to a heart attack.

Your result is an Agatston score: 0 means no calcified plaque, 1–10 is minimal, 11–100 mild, 101–400 moderate and above 400 severe. Your report also puts your score in relation to your age, since the same score means more when you're younger.